Object store mirroring

ABSTRACT

Techniques are provided for object store mirroring. Data within a storage tier of a node may be determined as being data to tier out to a primary object store based upon a property of the data. A first object is generated to comprise the data. A second object is generated to comprise the data. The first object is transmitted to the primary data store for storage in parallel with the second object being transmitted to a mirror object store for storage. Tiering of the data is designated as successful once acknowledgements are received from both the primary object that the first object was stored and the mirror object store that the second object was stored.

RELATED APPLICATION

This application claims priority to and is a continuation of U.S. patentapplication Ser. No. 16/389,019, titled “OBJECT STORE MIRRORING” andfiled on Apr. 19, 2019, which claims priority to and is a continuationof U.S. patent application Ser. No. 16/382,344, titled “OBJECT STOREMIRRORING” and filed on Apr. 12, 2019, which is incorporated herein byreference.

BACKGROUND

Many users store data within an object store, such as a cloud computingenvironment or other storage service hosted by a third party provider.In an example of storing and managing data, a user may utilize dedicatednodes, such as hardware and/or software (e.g., a storage virtualmachine), to store and access data. A node may manage one or more tiersof storage. For example, the node may manage a performance storage tierwithin which frequently accessed data is stored. The node may comprise acapacity tier within which infrequently accessed data is stored. Storagedevices within the capacity tier may be relatively cheaper but slowerthan storage devices within the performance tier.

The node may be configured to tier out (e.g., migrate, copy, relocate,etc.) certain data from a storage tier of the node to a remote objectstore. For example, infrequently accessed data (cold data) may betransmitted from the node to the remote object store as an object. Thismay be cost effective because storage provided by the remote objectstore may be cheaper and scalable, but slower (higher latency).Unfortunately, the remote object store may not provide adequateredundancy and availability for the objects stored from the storage tierto the remote object store since merely a single copy of each object ismaintained within a single remote object store. Even when there aremultiple copies of an object, the copies might be in the sameavailability zones from a disaster standpoint (e.g., a same building, asame room, or a same location/zone within which all nodes may beaffected by a disaster). For example, if an on-premises object store islocated in a lab, then multiple copies of an object may be stored ondifferent nodes of the on-premises object store. While a user can stillaccess a copy of the object if a node fails, the user cannot access anycopies if the entire on-premises object store has a disaster, such aswhere the lab burns down. If the remote object store is inaccessible dueto network issues, has a failure, loses an object, etc., then clientswill be unable to access data within the objects stored within theremote object store.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a component block diagram illustrating an example clusterednetwork in which an embodiment of the invention may be implemented.

FIG. 2 is a component block diagram illustrating an example data storagesystem in which an embodiment of the invention may be implemented.

FIG. 3 is a flow chart illustrating an example method for object storemirroring.

FIG. 4A is a component block diagram illustrating an example system forobject store mirroring, where a first storage bucket is attached to acomponent.

FIG. 4B is a component block diagram illustrating an example system forobject store mirroring, where data is tiered from a storage tier to aprimary object store.

FIG. 4C is a component block diagram illustrating an example system forobject store mirroring, where a second storage bucket is attached to acomponent.

FIG. 4D is a component block diagram illustrating an example system forobject store mirroring, where a second storage bucket is resynced usinga first storage bucket.

FIG. 4E is a component block diagram illustrating an example system forobject store mirroring, where data is tiered to a primary object storeand a mirror object store.

FIG. 4F is a component block diagram illustrating an example system forobject store mirroring, where data is read from objects within objectstores.

FIG. 4G is a component block diagram illustrating an example system forobject store mirroring, where a third storage bucket is created andresynced.

FIG. 4H is a component block diagram illustrating an example system forobject store mirroring, where a garbage collection process is performed.

FIG. 4I is a component block diagram illustrating an example system forobject store mirroring, where objects are migrated from a primary objectstore to a new object store.

FIG. 5 is an example of a computer readable medium in which anembodiment of the invention may be implemented.

FIG. 6 is a component block diagram illustrating an example computingenvironment in which an embodiment of the invention may be implemented.

DETAILED DESCRIPTION

Some examples of the claimed subject matter are now described withreference to the drawings, where like reference numerals are generallyused to refer to like elements throughout. In the following description,for purposes of explanation, numerous specific details are set forth inorder to provide an understanding of the claimed subject matter. It maybe evident, however, that the claimed subject matter may be practicedwithout these specific details. Nothing in this detailed description isadmitted as prior art.

A node, such as a computing device, a storage controller, a storagevirtual machine, a storage service, or any other hardware or software orcombination thereof, may store data within a storage tier. The storagetier may comprise dedicated storage device owned by the node (e.g.,locally attached storage or storage accessible to the node over anetwork). The node may tier out certain data from the storage tier to aprimary object store, such as infrequently accessed data. The data maybe stored into objects (e.g., an object may comprise slots such as 1024or any other number of slots into which data such as 4 kb or any othersize of data may be stored) that are then transmitted by the node to theprimary object store for storage.

As provided herein, additional redundancy and availability is providedby a component (e.g., hardware, software, or a combination thereof, suchas a storage virtual machine, a storage service, a node, a computer, acontroller, etc.) configured to mirror the objects of the primary objectstore to a mirror object store. In an example of a tiering operation,when an object is to be written to the primary object store, anotherobject comprising the same data is created for transmission to themirror object store. The object is transmitted to the primary objectstore in parallel with the other object being transmitted to the mirrorobject store. The tiering operation is not considered complete unlessboth the primary object store acknowledges the object as being storedand the mirror object store acknowledges the other object being storedand/or based upon both objects being validated as having valid data. Inthis way, the objects within the mirror object store are maintained asmirrored copies of the objects within the primary object store, thusimproving redundancy and availability.

The component also allows users to switch and migrate between differentobject store providers. This may be accomplished by attaching a storagebucket of another provider to the component, synchronizing objects fromthe primary object store to the storage bucket, swapping from using theprimary object store to using the storage bucket of the provider, andremoving the objects from the primary object store.

The component also allows users to improve performance where the primaryobject store may limit operations to a storage bucket. If the throughputof writing objects to and/or reading objects from the storage bucket isbelow a threshold, then a new storage bucket of the primary object storecan be attached to the component for tiering and/or mirroring data tothe new storage bucket. In an example, some objects may be migrated fromthe storage bucket to the new storage bucket to improve throughput tothose objects and the remaining objects within the storage bucket.

The component also allows users to swap from using a storage bucket tousing a new storage bucket. For example, a user may assign a wrong nameto the storage bucket during creation. Because the name may not bechanged, the storage bucket will retain the wrong name. Accordingly, thecomponent allows the user to create the new storage bucket, migrateobjects from the storage bucket to the new storage bucket, and deletethe storage bucket.

The component also provides for failover capabilities between objectsstores and/or nodes. For example, a storage tier of the node may bemirrored (e.g., synchronous replication of operations or asynchronousreplication of data) to a mirrored storage tier of another node so thatclient access to data can be failed over to the mirrored storage tier ifthe node fails. Similarly, the mirror object store is maintained as amirror of the primary object store so that access to objects can befailed over to the mirrored object store if the primary object storeencounters an issue (e.g., an object is lost, network access to theprimary object store is lost, the primary object store has a failure,etc.).

In this way, the component allows storage buckets to be added and/orremoved from various objects stores for tiering data from a storage tierof a node to the storage buckets. This improves redundancy andavailability because multiple copies of the same object can be storedwithin multiple object stores.

To provide for object store mirroring, FIG. 1 illustrates an embodimentof a clustered network environment 100 or a network storage environment.It may be appreciated, however, that the techniques, etc. describedherein may be implemented within the clustered network environment 100,a non-cluster network environment, and/or a variety of other computingenvironments, such as a desktop computing environment. That is, theinstant disclosure, including the scope of the appended claims, is notmeant to be limited to the examples provided herein. It will beappreciated that where the same or similar components, elements,features, items, modules, etc. are illustrated in later figures but werepreviously discussed with regard to prior figures, that a similar (e.g.,redundant) discussion of the same may be omitted when describing thesubsequent figures (e.g., for purposes of simplicity and ease ofunderstanding).

FIG. 1 is a block diagram illustrating the clustered network environment100 that may implement at least some embodiments of the techniquesand/or systems described herein. The clustered network environment 100comprises data storage systems 102 and 104 that are coupled over acluster fabric 106, such as a computing network embodied as a privateInfiniband, Fibre Channel (FC), or Ethernet network facilitatingcommunication between the data storage systems 102 and 104 (and one ormore modules, component, etc. therein, such as, nodes 116 and 118, forexample). It will be appreciated that while two data storage systems 102and 104 and two nodes 116 and 118 are illustrated in FIG. 1, that anysuitable number of such components is contemplated. In an example, nodes116, 118 comprise storage controllers (e.g., node 116 may comprise aprimary or local storage controller and node 118 may comprise asecondary or remote storage controller) that provide client devices,such as host devices 108, 110, with access to data stored within datastorage devices 128, 130. Similarly, unless specifically providedotherwise herein, the same is true for other modules, elements,features, items, etc. referenced herein and/or illustrated in theaccompanying drawings. That is, a particular number of components,modules, elements, features, items, etc. disclosed herein is not meantto be interpreted in a limiting manner.

It will be further appreciated that clustered networks are not limitedto any particular geographic areas and can be clustered locally and/orremotely. Thus, In an embodiment a clustered network can be distributedover a plurality of storage systems and/or nodes located in a pluralityof geographic locations; while In an embodiment a clustered network caninclude data storage systems (e.g., 102, 104) residing in a samegeographic location (e.g., in a single onsite rack of data storagedevices).

In the illustrated example, one or more host devices 108, 110 which maycomprise, for example, client devices, personal computers (PCs),computing devices used for storage (e.g., storage servers), and othercomputers or peripheral devices (e.g., printers), are coupled to therespective data storage systems 102, 104 by storage network connections112, 114. Network connection may comprise a local area network (LAN) orwide area network (WAN), for example, that utilizes Network AttachedStorage (NAS) protocols, such as a Common Internet File System (CIFS)protocol or a Network File System (NFS) protocol to exchange datapackets, a Storage Area Network (SAN) protocol, such as Small ComputerSystem Interface (SCSI) or Fiber Channel Protocol (FCP), an objectprotocol, such as S3, etc. Illustratively, the host devices 108, 110 maybe general-purpose computers running applications, and may interact withthe data storage systems 102, 104 using a client/server model forexchange of information. That is, the host device may request data fromthe data storage system (e.g., data on a storage device managed by anetwork storage control configured to process I/O commands issued by thehost device for the storage device), and the data storage system mayreturn results of the request to the host device via one or more storagenetwork connections 112, 114.

The nodes 116, 118 on clustered data storage systems 102, 104 cancomprise network or host nodes that are interconnected as a cluster toprovide data storage and management services, such as to an enterprisehaving remote locations, cloud storage (e.g., a storage endpoint may bestored within a data cloud), etc., for example. Such a node in theclustered network environment 100 can be a device attached to thenetwork as a connection point, redistribution point or communicationendpoint, for example. A node may be capable of sending, receiving,and/or forwarding information over a network communications channel, andcould comprise any device that meets any or all of these criteria. Oneexample of a node may be a data storage and management server attachedto a network, where the server can comprise a general purpose computeror a computing device particularly configured to operate as a server ina data storage and management system.

In an example, a first cluster of nodes such as the nodes 116, 118(e.g., a first set of storage controllers configured to provide accessto a first storage aggregate comprising a first logical grouping of oneor more storage devices) may be located on a first storage site. Asecond cluster of nodes, not illustrated, may be located at a secondstorage site (e.g., a second set of storage controllers configured toprovide access to a second storage aggregate comprising a second logicalgrouping of one or more storage devices). The first cluster of nodes andthe second cluster of nodes may be configured according to a disasterrecovery configuration where a surviving cluster of nodes providesswitchover access to storage devices of a disaster cluster of nodes inthe event a disaster occurs at a disaster storage site comprising thedisaster cluster of nodes (e.g., the first cluster of nodes providesclient devices with switchover data access to storage devices of thesecond storage aggregate in the event a disaster occurs at the secondstorage site).

As illustrated in the clustered network environment 100, nodes 116, 118can comprise various functional components that coordinate to providedistributed storage architecture for the cluster. For example, the nodescan comprise network modules 120, 122 and disk modules 124, 126. Networkmodules 120, 122 can be configured to allow the nodes 116, 118 (e.g.,network storage controllers) to connect with host devices 108, 110 overthe storage network connections 112, 114, for example, allowing the hostdevices 108, 110 to access data stored in the distributed storagesystem. Further, the network modules 120, 122 can provide connectionswith one or more other components through the cluster fabric 106. Forexample, in FIG. 1, the network module 120 of node 116 can access asecond data storage device by sending a request through the disk module126 of node 118.

Disk modules 124, 126 can be configured to connect one or more datastorage devices 128, 130, such as disks or arrays of disks, flashmemory, or some other form of data storage, to the nodes 116, 118. Thenodes 116, 118 can be interconnected by the cluster fabric 106, forexample, allowing respective nodes in the cluster to access data on datastorage devices 128, 130 connected to different nodes in the cluster.Often, disk modules 124, 126 communicate with the data storage devices128, 130 according to the SAN protocol, such as SCSI or FCP, forexample. Thus, as seen from an operating system on nodes 116, 118, thedata storage devices 128, 130 can appear as locally attached to theoperating system. In this manner, different nodes 116, 118, etc. mayaccess data blocks through the operating system, rather than expresslyrequesting abstract files.

It should be appreciated that, while the clustered network environment100 illustrates an equal number of network and disk modules, otherembodiments may comprise a differing number of these modules. Forexample, there may be a plurality of network and disk modulesinterconnected in a cluster that does not have a one-to-onecorrespondence between the network and disk modules. That is, differentnodes can have a different number of network and disk modules, and thesame node can have a different number of network modules than diskmodules.

Further, a host device 108, 110 can be networked with the nodes 116, 118in the cluster, over the storage networking connections 112, 114. As anexample, respective host devices 108, 110 that are networked to acluster may request services (e.g., exchanging of information in theform of data packets) of nodes 116, 118 in the cluster, and the nodes116, 118 can return results of the requested services to the hostdevices 108, 110. In an embodiment, the host devices 108, 110 canexchange information with the network modules 120, 122 residing in thenodes 116, 118 (e.g., network hosts) in the data storage systems 102,104.

In an embodiment, the data storage devices 128, 130 comprise volumes132, which is an implementation of storage of information onto diskdrives or disk arrays or other storage (e.g., flash) as a file-systemfor data, for example. In an example, a disk array can include alltraditional hard drives, all flash drives, or a combination oftraditional hard drives and flash drives. Volumes can span a portion ofa disk, a collection of disks, or portions of disks, for example, andtypically define an overall logical arrangement of file storage on diskspace in the storage system. In an embodiment a volume can comprisestored data as one or more files that reside in a hierarchical directorystructure within the volume.

Volumes are typically configured in formats that may be associated withparticular storage systems, and respective volume formats typicallycomprise features that provide functionality to the volumes, such asproviding an ability for volumes to form clusters. For example, where afirst storage system may utilize a first format for their volumes, asecond storage system may utilize a second format for their volumes.

In the clustered network environment 100, the host devices 108, 110 canutilize the data storage systems 102, 104 to store and retrieve datafrom the volumes 132. In this embodiment, for example, the host device108 can send data packets to the network module 120 in the node 116within data storage system 102. The node 116 can forward the data to thedata storage device 128 using the disk module 124, where the datastorage device 128 comprises volume 132A. In this way, in this example,the host device can access the volume 132A, to store and/or retrievedata, using the data storage system 102 connected by the storage networkconnection 112. Further, in this embodiment, the host device 110 canexchange data with the network module 122 in the node 118 within thedata storage system 104 (e.g., which may be remote from the data storagesystem 102). The node 118 can forward the data to the data storagedevice 130 using the disk module 126, thereby accessing volume 1328associated with the data storage device 130.

It may be appreciated that object store mirroring may be implementedwithin the clustered network environment 100. It may be appreciated thatobject store mirroring may be implemented for and/or between any type ofcomputing environment, and may be transferrable between physical devices(e.g., node 116, node 118, a desktop computer, a tablet, a laptop, awearable device, a mobile device, a storage device, a server, etc.)and/or a cloud computing environment (e.g., remote to the clusterednetwork environment 100).

FIG. 2 is an illustrative example of a data storage system 200 (e.g.,102, 104 in FIG. 1), providing further detail of an embodiment ofcomponents that may implement one or more of the techniques and/orsystems described herein. The data storage system 200 comprises a node202 (e.g., nodes 116, 118 in FIG. 1), and a data storage device 234(e.g., data storage devices 128, 130 in FIG. 1). The node 202 may be ageneral purpose computer, for example, or some other computing deviceparticularly configured to operate as a storage server. A host device205 (e.g., 108, 110 in FIG. 1) can be connected to the node 202 over anetwork 216, for example, to provide access to files and/or other datastored on the data storage device 234. In an example, the node 202comprises a storage controller that provides client devices, such as thehost device 205, with access to data stored within data storage device234.

The data storage device 234 can comprise mass storage devices, such asdisks 224, 226, 228 of a disk array 218, 220, 222. It will beappreciated that the techniques and systems, described herein, are notlimited by the example embodiment. For example, disks 224, 226, 228 maycomprise any type of mass storage devices, including but not limited tomagnetic disk drives, flash memory, and any other similar media adaptedto store information, including, for example, data (D) and/or parity (P)information.

The node 202 comprises one or more processors 204, a memory 206, anetwork adapter 210, a cluster access adapter 212, and a storage adapter214 interconnected by a system bus 242. The data storage system 200 alsoincludes an operating system 208 installed in the memory 206 of the node202 that can, for example, implement a Redundant Array of Independent(or Inexpensive) Disks (RAID) optimization technique to optimize areconstruction process of data of a failed disk in an array.

The operating system 208 can also manage communications for the datastorage system, and communications between other data storage systemsthat may be in a clustered network, such as attached to a cluster fabric215 (e.g., 106 in FIG. 1). Thus, the node 202, such as a network storagecontroller, can respond to host device requests to manage data on thedata storage device 234 (e.g., or additional clustered devices) inaccordance with these host device requests. The operating system 208 canoften establish one or more file systems on the data storage system 200,where a file system can include software code and data structures thatimplement a persistent hierarchical namespace of files and directories,for example. As an example, when a new data storage device (not shown)is added to a clustered network system, the operating system 208 isinformed where, in an existing directory tree, new files associated withthe new data storage device are to be stored. This is often referred toas “mounting” a file system.

In the example data storage system 200, memory 206 can include storagelocations that are addressable by the processors 204 and adapters 210,212, 214 for storing related software application code and datastructures. The processors 204 and adapters 210, 212, 214 may, forexample, include processing elements and/or logic circuitry configuredto execute the software code and manipulate the data structures. Theoperating system 208, portions of which are typically resident in thememory 206 and executed by the processing elements, functionallyorganizes the storage system by, among other things, invoking storageoperations in support of a file service implemented by the storagesystem. It will be apparent to those skilled in the art that otherprocessing and memory mechanisms, including various computer readablemedia, may be used for storing and/or executing application instructionspertaining to the techniques described herein. For example, theoperating system can also utilize one or more control files (not shown)to aid in the provisioning of virtual machines.

The network adapter 210 includes the mechanical, electrical andsignaling circuitry needed to connect the data storage system 200 to ahost device 205 over a network 216, which may comprise, among otherthings, a point-to-point connection or a shared medium, such as a localarea network. The host device 205 (e.g., 108, 110 of FIG. 1) may be ageneral-purpose computer configured to execute applications. Asdescribed above, the host device 205 may interact with the data storagesystem 200 in accordance with a client/host model of informationdelivery.

The storage adapter 214 cooperates with the operating system 208executing on the node 202 to access information requested by the hostdevice 205 (e.g., access data on a storage device managed by a networkstorage controller). The information may be stored on any type ofattached array of writeable media such as magnetic disk drives, flashmemory, and/or any other similar media adapted to store information. Inthe example data storage system 200, the information can be stored indata blocks on the disks 224, 226, 228. The storage adapter 214 caninclude input/output (I/O) interface circuitry that couples to the disksover an I/O interconnect arrangement, such as a storage area network(SAN) protocol (e.g., Small Computer System Interface (SCSI), iSCSI,hyperSCSI, Fiber Channel Protocol (FCP)). The information is retrievedby the storage adapter 214 and, if necessary, processed by the one ormore processors 204 (or the storage adapter 214 itself) prior to beingforwarded over the system bus 242 to the network adapter 210 (and/or thecluster access adapter 212 if sending to another node in the cluster)where the information is formatted into a data packet and returned tothe host device 205 over the network 216 (and/or returned to anothernode attached to the cluster over the cluster fabric 215).

In an embodiment, storage of information on disk arrays 218, 220, 222can be implemented as one or more storage volumes 230, 232 that arecomprised of a cluster of disks 224, 226, 228 defining an overalllogical arrangement of disk space. The disks 224, 226, 228 that compriseone or more volumes are typically organized as one or more groups ofRAIDs. As an example, volume 230 comprises an aggregate of disk arrays218 and 220, which comprise the cluster of disks 224 and 226.

In an embodiment, to facilitate access to disks 224, 226, 228, theoperating system 208 may implement a file system (e.g., write anywherefile system) that logically organizes the information as a hierarchicalstructure of directories and files on the disks. In this embodiment,respective files may be implemented as a set of disk blocks configuredto store information, whereas directories may be implemented asspecially formatted files in which information about other files anddirectories are stored.

Whatever the underlying physical configuration within this data storagesystem 200, data can be stored as files within physical and/or virtualvolumes, which can be associated with respective volume identifiers,such as file system identifiers (FSIDs), which can be 32-bits in lengthin one example.

A physical volume corresponds to at least a portion of physical storagedevices whose address, addressable space, location, etc. doesn't change,such as at least some of one or more data storage devices 234 (e.g., aRedundant Array of Independent (or Inexpensive) Disks (RAID system)).Typically the location of the physical volume doesn't change in that the(range of) address(es) used to access it generally remains constant.

A virtual volume, in contrast, is stored over an aggregate of disparateportions of different physical storage devices. The virtual volume maybe a collection of different available portions of different physicalstorage device locations, such as some available space from each of thedisks 224, 226, and/or 228. It will be appreciated that since a virtualvolume is not “tied” to any one particular storage device, a virtualvolume can be said to include a layer of abstraction or virtualization,which allows it to be resized and/or flexible in some regards.

Further, a virtual volume can include one or more logical unit numbers(LUNs) 238, directories 236, Qtrees 235, and files 240. Among otherthings, these features, but more particularly LUNS, allow the disparatememory locations within which data is stored to be identified, forexample, and grouped as data storage unit. As such, the LUNs 238 may becharacterized as constituting a virtual disk or drive upon which datawithin the virtual volume is stored within the aggregate. For example,LUNs are often referred to as virtual drives, such that they emulate ahard drive from a general purpose computer, while they actually comprisedata blocks stored in various parts of a volume.

In an embodiment, one or more data storage devices 234 can have one ormore physical ports, wherein each physical port can be assigned a targetaddress (e.g., SCSI target address). To represent respective volumesstored on a data storage device, a target address on the data storagedevice can be used to identify one or more LUNs 238. Thus, for example,when the node 202 connects to a volume 230, 232 through the storageadapter 214, a connection between the node 202 and the one or more LUNs238 underlying the volume is created.

In an embodiment, respective target addresses can identify multipleLUNs, such that a target address can represent multiple volumes. The I/Ointerface, which can be implemented as circuitry and/or software in thestorage adapter 214 or as executable code residing in memory 206 andexecuted by the processors 204, for example, can connect to volume 230by using one or more addresses that identify the one or more LUNs 238.

It may be appreciated that object store mirroring may be implemented forthe data storage system 200. It may be appreciated that object storemirroring may be implemented for and/or between any type of computingenvironment, and may be transferrable between physical devices (e.g.,node 202, host device 205, a desktop computer, a tablet, a laptop, awearable device, a mobile device, a storage device, a server, etc.)and/or a cloud computing environment (e.g., remote to the node 202and/or the host device 205).

One embodiment of object store mirroring is illustrated by an exemplarymethod 300 of FIG. 3 and further described in conjunction with system400 of FIGS. 4A-4I. A node 402, such as a computer, a storagecontroller, a server, a storage virtual machine, a storage service,hardware, software, or a combination hardware and software, may beconfigured to provide client devices with access to data stored withinone or more storage tiers (e.g., locally attached storage, storageaccessible over a local network, etc.). For example, the node 402 maystore frequently accessed data within a storage tier 404, as illustratedby FIG. 4A. In an example, the node 402 may be paired with a second nodenot illustrated. Data may be synchronously or asynchronously replicatedfrom the storage tier 404 of the node 402 to storage managed by thesecond node, such as a mirror storage tier of the second node. Thus, ifthe node 402 fails, the second node can provide clients with access toreplicated data within the storage of the second node. In this way, afailover operation can be performed to redirect access operations fromthe storage tier 404 to the storage of the second node.

Because the storage tier 404 of the node 402 may be relatively moreexpensive and less scalable than object storage provided by an objectstore (e.g., a cloud provider may provide low cost scalable cloudstorage), it would be beneficial to tier off (e.g., migrate, relocate,etc.) certain types of data. Because the storage tier 404 may be fasterthan object storage, frequently accessed data (hot data) may be storedwithin the storage tier 404 so that client devices can quickly accesssuch data through the node 402. Infrequently accessed data (cold data)may be tiered off from the storage tier 404 to the object storage.

Accordingly, a component 406 (e.g., a computer, a storage controller, aserver, a storage virtual machine, a service, hardware, software, or acombination hardware and software) is configured to manage the tieringof data to one or more object stores. The component 406 may beimplemented within the node 402, within a separate computing device, orwithin an object store. In an example, the component 406 may establish aconnection with a primary object store 408 over a network. The primaryobject store 408 may be hosted by a third party provider such as a cloudservice provider. The component 406 may create 412 a first storagebucket 414 within the primary object store 408. The first storage bucket414 may correspond to a logical designation of storage by the primaryobject store 408 that can be used to by the component 406 to storeobjects.

The node 402 or the component 406 may identify data 416 to be tiered outfrom the storage tier 404 to the primary object store 408, asillustrated by FIG. 4B. The data 416 may be identified based upon aproperty of the data 416, such as a timestamp indicating that the data416 has not been access within a threshold timespan or another propertyindicating that the data 416 is infrequently accessed. As a thresholdamount of data 416 is identified for tiering, an object may be createdto comprise the data 416. The object may comprise a number of slots,such as 1024 or any other number of slots, into which a certain amountof the data 416 can be stored (e.g., each slot may comprise up to 4 kbof data or any other designated size). Once enough data 416 isidentified for tiering to fill an object, then the object may be createdto comprise the data 416 within the slots. The object may comprise aheader with various information used to access the data 416 within theslots. The object may be assigned a unique sequence identifier, and maybe assigned a name that may be based upon the primary object store 408.In this way, the component 406 creates objects 418 of the data 416 andstores those objects 418 within the first storage bucket 414 of theprimary object store 408.

In order to improve redundancy and availability, the component 406 maycreate 422 a second storage bucket 424 within a mirror object store 410,as illustrated by FIG. 4C. In an example, the primary object store 408may be hosted by a first provider and the mirror object store 410 may behosted by a second different provider. Thus, a failure, connectivityissue, or other issue of the primary object store 408 may not affect themirror object store 410. In this way, the component 406 may storeobjects within the second storage bucket 424 that mirror the objects 418within the first storage bucket 414 so that a failover operation can beperformed to redirect access operations from the primary object store408 to the mirror object store 410 in the event the primary object store408 and/or one or more objects stored therein are unavailable.

Initially, the second storage bucket 424 does not comprise objects.Accordingly, the component 406 performs a resync operation 428 in orderto populate the second storage bucket 424 with objects, such as mirroredobjects 438 corresponding to the objects 418 within the first storagebucket 414, as illustrated by FIG. 4D. As part of the resync operation428, the component 406 reads 430 the objects 418 from the first storagebucket 414. In an example, the objects 418 may be sequentially read fromobjects having a smallest object identifier to objects having a largestobject identifier or any other type of ordering. Objects that have areference count of zero (e.g., objects no longer being referenced by afile system of the node 402, and thus can be deleted by a garbagecollection process) and objects having a creating state (e.g., objectsthat not have yet been verified as being successfully stored with validdata) may be skipped by the resync operation 428.

As part of the resync operation 428, the component 406 may read anobject from the first storage bucket 414. The component 406 may create amirrored object to comprise the data within the object. The mirroredobject may be assigned a different name than the object, such as a namederived from the mirror object store 410. When creating the mirroredobject, the data within the object may be encrypted. To improve theefficiency of the resync operation 428, the data is maintained in theencrypted state when stored within the mirrored object so that nodecryption and re-encryption is necessary. In the event the resyncoperation 428 stops or is interrupted (e.g., client access to objectshas a higher priority than the resync operation 428, and thus the resyncoperation 428 may be suspended at times so that the resync operation 428does not increase latency of clients accessing objects within theprimary object store 408), checkpoints are created. A checkpointindicates which object of the first storage bucket 414 was last used tosuccessfully create a mirrored object that was successfully stored andverified as having valid data within the mirror object store 410. Thecheckpoint can thus be used by the component 406 to resume the resyncoperation 428 where it was left off. In this way, the component 406executes the resync operation 428 to create mirrored objects 438 thatare transmitted 432 to the mirror object store 410 for storage withinthe second storage bucket 424. During the resync operation 428, thecomponent 406 may continue to tier 436 data 434 from the storage tier404 into objects for storage within the first storage bucket 414 and thesecond storage bucket 424.

FIG. 4E illustrates an example of tiering data 440 to both the primaryobject store 408 and the mirror object store 410. The data 440 withinthe storage tier 404 may be determined to be set for being tiered outbased upon a property of the data, at 302. For example, the data 440 maybe identified as infrequently accessed data 440, and thus is set forbeing tiered out from the storage tier 404 to the primary object store408 and the mirror object store 410. At 304, the component 406 creates afirst object 442 and stores the data 440 into the slots of the firstobject 442. The first object 442 may be assigned a first name derivedfrom the primary object store 408. At 306, the component 406 creates asecond object 444 and stores the data 440 into slots of the secondobject 444. In this way, the first object 442 and the second object 444comprise the same data 440. The second object 444 may be assigned asecond name derived from the mirror object store 410. The component 406may assign a creating state to the first object 442 and the secondobject 444 to indicate that the objects have not yet been successfullytiered out with valid data.

At 308, the first object 442 is transmitted to the primary object store408 for storage within the first storage bucket 414 in parallel with thesecond object 444 being transmitted to the mirror object store 410 forstorage within the second storage bucket 424. The component 406 may waitfor the primary object store 408 to send a first acknowledgement thatthe first object 442 was successfully stored and for the mirror objectstore 410 to send a second acknowledgement that the second object 444was successfully stored. In one example, upon receiving both the firstacknowledgement and the second acknowledgement, the component 406 maydesignate the data 440 as being successfully tiered out, at 310. Inanother example, the component 406 performs an additional check beforedesignating the data 440 as being successfully tiered out. For example,the component 406 may read a first header of the first object 442 withinthe first storage bucket 414 to verify that the first object 442comprises the actual data 440 (valid data). The component 406 may read asecond header of the second object 444 within the second storage bucket424 to verify that the second object 444 comprises the actual data 440(valid data). Once the component 406 has verified that both the firstobject 442 and the second object 444 comprise the actual data 440 (validdata), then the component 406 may designate the data 440 as beingsuccessfully tiered out. Once the data 440 has been designated as beingsuccessfully tiered out, a state of the first object 442 and the secondobject 444 may be modified from the creating state to a valid stateindicating that the first object 442 and the second object 444 arevalid.

If either the first acknowledgement or the second acknowledgement arenot received by the component 406 or either the first object 442 and thesecond object 444 do not comprise valid/expected data 440 after beingstored to the object stores, the tiering out of the data 440 isdesignated as being unsuccessful. That is, the tiering out is onlysuccessfully if both objects are successfully stored with valid/expecteddata 440 within both object stores. If the tiering out is unsuccessful,then the tiering out may be retried by retransmitting the first object442 to the primary object store 408 for storage within the first storagebucket 414 (irrespective of whether the first object 442 wassuccessfully stored with valid data during the first attempt) inparallel with the second object 444 being retransmitted with the mirrorobject store 410 for storage within the second storage bucket 424(irrespective of whether the second object 444 was successfully storedwith valid data during the first attempt). In this way, the first object442 is stored among the objects 418 within the first storage bucket 414and the second object 444 is stored amongst the mirrored objects 438within the second storage bucket 424.

FIG. 4F illustrates the component 406 facilitating 452 a read operation450 to access data within the first object 442 of the first storagebucket 414 within the primary object store 408. Upon receiving the readoperation 450, the component 406 transmits a read request 454 to theprimary object store 408 for the first object 442 comprising therequested data. If the first object 442 is received from the primaryobject store 408, then the request data of the first object 442 isreturned to the node 402. However, if the read request 454 fails (e.g.,fails a threshold number of times), the component 406 may retry the readrequest 454 as a retry read request 456 that is transmitted to themirror object store 410 to read the second object 444 comprising thesame requested data as the first object 442. If the second object 444 isreceived from the mirror object store 410, then the request data of thesecond object 444 is returned to the node 402. If the failed readrequest 454 indicated that the first object 442 was not found, then thedata of the second object 444 may be used to create a new first objectthat is transmitted to the primary object store 408 for storage withinthe first storage bucket 414 in place of the lost first object 442.

FIG. 4G illustrates the component 406 creating 460 a third storagebucket 464 within the primary object store 408. For example, thecomponent 406 may determine that performance (e.g., latency ofprocessing read and write operations to the primary object store 408) isbelow a threshold. Degraded performance may be due to the primary objectstore 408 limiting the number of operations to the first storage bucket414 over a period of time. Accordingly, the component 406 creates 460the third storage bucket 464 within the primary object store 408. Thethird storage bucket 464 may initially be empty of objects. In anexample, once the third storage bucket 464 is created, new data to tierto the primary object store 408 may be stored as objects within thethird bucket 464 as opposed to the first storage bucket 414. In anotherexample, the component 406 may perform a resync operation 462 to read asubset of objects within the first storage bucket 414. Data within thesubset of objects may be used to create a set of objects mirroring thesubset of objects. The subset of objects are stored into the thirdstorage bucket 464. The subset of objects may be removed from the firststorage bucket 414. In this way, the objects 418 of the first storagebucket 414 may be spread amongst the first storage bucket 414 and thethird storage bucket 464 to improve performance. In another example, allobjects of the first storage bucket 414 may be copied to the thirdstorage bucket 464. Then, read operations can be sent to either thefirst storage bucket 414 or the third storage bucket 464, such as in around robin manner or other load balancing fashion in order todistribute the read operations amongst the buckets (e.g., roughlycutting read operations to each bucket in half).

In another example, the third storage bucket 464 may be created basedupon a parameter of the first storage bucket 414 being incorrect, suchas where the first storage bucket 414 was incorrectly named whencreated. Accordingly, the resync operation 462 can be performed to readthe objects 418 from the first storage bucket 414, create new objectsmirroring the objects 418, store the new objects within the thirdstorage bucket 464, and detach and delete the first storage bucket 414.

FIG. 4H illustrates the component 406 performing a garbage collectionprocess 472. A file system of the node 402 may be evaluated to identifydata 470 no longer being referenced by the file system, such as due tobeing deleted. An object within an object store may comprise the data470 that is no longer referenced by the file system. In an example, theobject may not be deleted immediately because the object may alsocomprise other data still referenced by the file system. Accordingly,the garbage collection process 472 can determine whether all data withinan object is no longer referenced by the file system. In an example, thegarbage collection process 472 may determine that all data within thefirst object 442 of the primary object store 408 and mirrored within thesecond object 444 of the mirror object store 410 is no longerreferenced. The garbage collection process 472 transmits a first deleteoperation 474 to the primary object store 408 to delete the first object442 from the first storage bucket 414 in parallel with transmitting asecond delete operation 476 to the mirror object store 410 to delete thesecond object 444 from the second storage bucket 424. In an example, thegarbage collection process 472 may be performed during a resyncoperation that could cause one of the object to already be deleted ormissing. Thus, the garbage collection process 472 may be deemedsuccessful even if an acknowledgement is received back for only one ofthe delete operations.

FIG. 4I illustrates the component 406 facilitating a migration 480 fromusing the primary object store 408 to using a new object store 484(e.g., an object store of a different provider than the provider of theprimary object store 408). The component 406 accesses the new objectstore 484, and creates a new storage bucket 486 within the new objectstore 484. The component 406 retrieves the objects 418 within the firststorage bucket 414 from the primary object store 408. The component 406creates migrated objects 482 comprising the data within the objects 418,and stores the migrated objects 482 into the new storage bucket 486 ofthe new object store 484. In this way, read operations for data withinthe objects 418 and write operations to the objects 418 are redirectedto the new object store 484. The objects 418 and/or the first storagebucket 414 are detached and deleted from the primary object store 408once the migrated objects 482 are verified as being stored with validdata.

Still another embodiment involves a computer-readable medium 500comprising processor-executable instructions configured to implement oneor more of the techniques presented herein. An example embodiment of acomputer-readable medium or a computer-readable device that is devisedin these ways is illustrated in FIG. 5, wherein the implementationcomprises a computer-readable medium 508, such as a compactdisc-recordable (CD-R), a digital versatile disc-recordable (DVD-R),flash drive, a platter of a hard disk drive, etc., on which is encodedcomputer-readable data 506. This computer-readable data 506, such asbinary data comprising at least one of a zero or a one, in turncomprises a processor-executable computer instructions 504 configured tooperate according to one or more of the principles set forth herein. Insome embodiments, the processor-executable computer instructions 504 areconfigured to perform a method 502, such as at least some of theexemplary method 300 of FIG. 3, for example. In some embodiments, theprocessor-executable computer instructions 504 are configured toimplement a system, such as at least some of the exemplary system 400 ofFIGS. 4A-4I, for example. Many such computer-readable media arecontemplated to operate in accordance with the techniques presentedherein.

FIG. 6 is a diagram illustrating an example operating environment 600 inwhich an embodiment of the techniques described herein may beimplemented. In one example, the techniques described herein may beimplemented within a client device 628, such as a laptop, tablet,personal computer, mobile device, wearable device, etc. In anotherexample, the techniques described herein may be implemented within astorage controller 630, such as a node configured to manage the storageand access to data on behalf of the client device 628 and/or otherclient devices. In another example, the techniques described herein maybe implemented within a distributed computing platform 602 such as acloud computing environment (e.g., a cloud storage environment, amulti-tenant platform, etc.) configured to manage the storage and accessto data on behalf of the client device 628 and/or other client devices.

In yet another example, at least some of the techniques described hereinare implemented across one or more of the client device 628, the storagecontroller 630, and the distributed computing platform 602. For example,the client device 628 may transmit operations, such as data operationsto read data and write data and metadata operations (e.g., a create fileoperation, a rename directory operation, a resize operation, a setattribute operation, etc.), over a network 626 to the storage controller630 for implementation by the storage controller 630 upon storage. Thestorage controller 630 may store data associated with the operationswithin volumes or other data objects/structures hosted within locallyattached storage, remote storage hosted by other computing devicesaccessible over the network 626, storage provided by the distributedcomputing platform 602, etc. The storage controller 630 may replicatethe data and/or the operations to other computing devices so that one ormore replicas, such as a destination storage volume that is maintainedas a replica of a source storage volume, are maintained. Such replicascan be used for disaster recovery and failover.

The storage controller 630 may store the data or a portion thereofwithin storage hosted by the distributed computing platform 602 bytransmitting the data to the distributed computing platform 602. In oneexample, the storage controller 630 may locally store frequentlyaccessed data within locally attached storage. Less frequently accesseddata may be transmitted to the distributed computing platform 602 forstorage within a data storage tier 608. The data storage tier 608 maystore data within a service data store 620, and may store clientspecific data within client data stores assigned to such clients such asa client (1) data store 622 used to store data of a client (1) and aclient (N) data store 624 used to store data of a client (N). The datastores may be physical storage devices or may be defined as logicalstorage, such as a virtual volume, LUNs, or other logical organizationsof data that can be defined across one or more physical storage devices.In another example, the storage controller 630 transmits and stores allclient data to the distributed computing platform 602. In yet anotherexample, the client device 628 transmits and stores the data directly tothe distributed computing platform 602 without the use of the storagecontroller 630.

The management of storage and access to data can be performed by one ormore storage virtual machines (SMVs) or other storage applications thatprovide software as a service (SaaS) such as storage software services.In one example, an SVM may be hosted within the client device 628,within the storage controller 630, or within the distributed computingplatform 602 such as by the application server tier 606. In anotherexample, one or more SVMs may be hosted across one or more of the clientdevice 628, the storage controller 630, and the distributed computingplatform 602.

In one example of the distributed computing platform 602, one or moreSVMs may be hosted by the application server tier 606. For example, aserver (1) 616 is configured to host SVMs used to execute applicationssuch as storage applications that manage the storage of data of theclient (1) within the client (1) data store 622. Thus, an SVM executingon the server (1) 616 may receive data and/or operations from the clientdevice 628 and/or the storage controller 630 over the network 626. TheSVM executes a storage application to process the operations and/orstore the data within the client (1) data store 622. The SVM maytransmit a response back to the client device 628 and/or the storagecontroller 630 over the network 626, such as a success message or anerror message. In this way, the application server tier 606 may hostSVMs, services, and/or other storage applications using the server (1)616, the server (N) 618, etc.

A user interface tier 604 of the distributed computing platform 602 mayprovide the client device 628 and/or the storage controller 630 withaccess to user interfaces associated with the storage and access of dataand/or other services provided by the distributed computing platform602. In an example, a service user interface 610 may be accessible fromthe distributed computing platform 602 for accessing services subscribedto by clients and/or storage controllers, such as data replicationservices, application hosting services, data security services, humanresource services, warehouse tracking services, accounting services,etc. For example, client user interfaces may be provided tocorresponding clients, such as a client (1) user interface 612, a client(N) user interface 614, etc. The client (1) can access various servicesand resources subscribed to by the client (1) through the client (1)user interface 612, such as access to a web service, a developmentenvironment, a human resource application, a warehouse trackingapplication, and/or other services and resources provided by theapplication server tier 606, which may use data stored within the datastorage tier 608.

The client device 628 and/or the storage controller 630 may subscribe tocertain types and amounts of services and resources provided by thedistributed computing platform 602. For example, the client device 628may establish a subscription to have access to three virtual machines, acertain amount of storage, a certain type/amount of data redundancy, acertain type/amount of data security, certain service level agreements(SLAs) and service level objectives (SLOs), latency guarantees,bandwidth guarantees, access to execute or host certain applications,etc. Similarly, the storage controller 630 can establish a subscriptionto have access to certain services and resources of the distributedcomputing platform 602.

As shown, a variety of clients, such as the client device 628 and thestorage controller 630, incorporating and/or incorporated into a varietyof computing devices may communicate with the distributed computingplatform 602 through one or more networks, such as the network 626. Forexample, a client may incorporate and/or be incorporated into a clientapplication (e.g., software) implemented at least in part by one or moreof the computing devices.

Examples of suitable computing devices include personal computers,server computers, desktop computers, nodes, storage servers, storagecontrollers, laptop computers, notebook computers, tablet computers orpersonal digital assistants (PDAs), smart phones, cell phones, andconsumer electronic devices incorporating one or more computing devicecomponents, such as one or more electronic processors, microprocessors,central processing units (CPU), or controllers. Examples of suitablenetworks include networks utilizing wired and/or wireless communicationtechnologies and networks operating in accordance with any suitablenetworking and/or communication protocol (e.g., the Internet). In usecases involving the delivery of customer support services, the computingdevices noted represent the endpoint of the customer support deliveryprocess, i.e., the consumer's device.

The distributed computing platform 602, such as a multi-tenant businessdata processing platform or cloud computing environment, may includemultiple processing tiers, including the user interface tier 604, theapplication server tier 606, and a data storage tier 608. The userinterface tier 604 may maintain multiple user interfaces, includinggraphical user interfaces and/or web-based interfaces. The userinterfaces may include the service user interface 610 for a service toprovide access to applications and data for a client (e.g., a “tenant”)of the service, as well as one or more user interfaces that have beenspecialized/customized in accordance with user specific requirements,which may be accessed via one or more APIs.

The service user interface 610 may include components enabling a tenantto administer the tenant's participation in the functions andcapabilities provided by the distributed computing platform 602, such asaccessing data, causing execution of specific data processingoperations, etc. Each processing tier may be implemented with a set ofcomputers, virtualized computing environments such as a storage virtualmachine or storage virtual server, and/or computer components includingcomputer servers and processors, and may perform various functions,methods, processes, or operations as determined by the execution of asoftware application or set of instructions.

The data storage tier 608 may include one or more data stores, which mayinclude the service data store 620 and one or more client data stores.Each client data store may contain tenant-specific data that is used aspart of providing a range of tenant-specific business and storageservices or functions, including but not limited to ERP, CRM, eCommerce,Human Resources management, payroll, storage services, etc. Data storesmay be implemented with any suitable data storage technology, includingstructured query language (SQL) based relational database managementsystems (RDBMS), file systems hosted by operating systems, objectstorage, etc.

In accordance with one embodiment of the invention, the distributedcomputing platform 602 may be a multi-tenant and service platformoperated by an entity in order to provide multiple tenants with a set ofbusiness related applications, data storage, and functionality. Theseapplications and functionality may include ones that a business uses tomanage various aspects of its operations. For example, the applicationsand functionality may include providing web-based access to businessinformation systems, thereby allowing a user with a browser and anInternet or intranet connection to view, enter, process, or modifycertain types of business information or any other type of information.

In an embodiment, the described methods and/or their equivalents may beimplemented with computer executable instructions. Thus, in anembodiment, a non-transitory computer readable/storage medium isconfigured with stored computer executable instructions of analgorithm/executable application that when executed by a machine(s)cause the machine(s) (and/or associated components) to perform themethod. Example machines include but are not limited to a processor, acomputer, a server operating in a cloud computing system, a serverconfigured in a Software as a Service (SaaS) architecture, a smartphone, and so on). In an embodiment, a computing device is implementedwith one or more executable algorithms that are configured to performany of the disclosed methods.

It will be appreciated that processes, architectures and/or proceduresdescribed herein can be implemented in hardware, firmware and/orsoftware. It will also be appreciated that the provisions set forthherein may apply to any type of special-purpose computer (e.g., filehost, storage server and/or storage serving appliance) and/orgeneral-purpose computer, including a standalone computer or portionthereof, embodied as or including a storage system. Moreover, theteachings herein can be configured to a variety of storage systemarchitectures including, but not limited to, a network-attached storageenvironment and/or a storage area network and disk assembly directlyattached to a client or host computer. Storage system should thereforebe taken broadly to include such arrangements in addition to anysubsystems configured to perform a storage function and associated withother equipment or systems.

In some embodiments, methods described and/or illustrated in thisdisclosure may be realized in whole or in part on computer-readablemedia. Computer readable media can include processor-executableinstructions configured to implement one or more of the methodspresented herein, and may include any mechanism for storing this datathat can be thereafter read by a computer system. Examples of computerreadable media include (hard) drives (e.g., accessible via networkattached storage (NAS)), Storage Area Networks (SAN), volatile andnon-volatile memory, such as read-only memory (ROM), random-accessmemory (RAM), electrically erasable programmable read-only memory(EEPROM) and/or flash memory, compact disk read only memory (CD-ROM)s,CD-Rs, compact disk re-writeable (CD-RW)s, DVDs, cassettes, magnetictape, magnetic disk storage, optical or non-optical data storage devicesand/or any other medium which can be used to store data.

Although the subject matter has been described in language specific tostructural features or methodological acts, it is to be understood thatthe subject matter defined in the appended claims is not necessarilylimited to the specific features or acts described above. Rather, thespecific features and acts described above are disclosed as exampleforms of implementing at least some of the claims.

Various operations of embodiments are provided herein. The order inwhich some or all of the operations are described should not beconstrued to imply that these operations are necessarily orderdependent. Alternative ordering will be appreciated given the benefit ofthis description. Further, it will be understood that not all operationsare necessarily present in each embodiment provided herein. Also, itwill be understood that not all operations are necessary in someembodiments.

Furthermore, the claimed subject matter is implemented as a method,apparatus, or article of manufacture using standard application orengineering techniques to produce software, firmware, hardware, or anycombination thereof to control a computer to implement the disclosedsubject matter. The term “article of manufacture” as used herein isintended to encompass a computer application accessible from anycomputer-readable device, carrier, or media. Of course, manymodifications may be made to this configuration without departing fromthe scope or spirit of the claimed subject matter.

As used in this application, the terms “component”, “module,” “system”,“interface”, and the like are generally intended to refer to acomputer-related entity, either hardware, a combination of hardware andsoftware, software, or software in execution. For example, a componentincludes a process running on a processor, a processor, an object, anexecutable, a thread of execution, an application, or a computer. By wayof illustration, both an application running on a controller and thecontroller can be a component. One or more components residing within aprocess or thread of execution and a component may be localized on onecomputer or distributed between two or more computers.

Moreover, “exemplary” is used herein to mean serving as an example,instance, illustration, etc., and not necessarily as advantageous. Asused in this application, “or” is intended to mean an inclusive “or”rather than an exclusive “or”. In addition, “a” and “an” as used in thisapplication are generally be construed to mean “one or more” unlessspecified otherwise or clear from context to be directed to a singularform. Also, at least one of A and B and/or the like generally means A orB and/or both A and B. Furthermore, to the extent that “includes”,“having”, “has”, “with”, or variants thereof are used, such terms areintended to be inclusive in a manner similar to the term “comprising”.

Many modifications may be made to the instant disclosure withoutdeparting from the scope or spirit of the claimed subject matter. Unlessspecified otherwise, “first,” “second,” or the like are not intended toimply a temporal aspect, a spatial aspect, an ordering, etc. Rather,such terms are merely used as identifiers, names, etc. for features,elements, items, etc. For example, a first set of information and asecond set of information generally correspond to set of information Aand set of information B or two different or two identical sets ofinformation or the same set of information.

Also, although the disclosure has been shown and described with respectto one or more implementations, equivalent alterations and modificationswill occur to others skilled in the art based upon a reading andunderstanding of this specification and the annexed drawings. Thedisclosure includes all such modifications and alterations and islimited only by the scope of the following claims. In particular regardto the various functions performed by the above described components(e.g., elements, resources, etc.), the terms used to describe suchcomponents are intended to correspond, unless otherwise indicated, toany component which performs the specified function of the describedcomponent (e.g., that is functionally equivalent), even though notstructurally equivalent to the disclosed structure. In addition, while aparticular feature of the disclosure may have been disclosed withrespect to only one of several implementations, such feature may becombined with one or more other features of the other implementations asmay be desired and advantageous for any given or particular application.

What is claimed is:
 1. A method comprising: identifying a first set ofobjects within a first object store to mirror to a second object store;and performing an operation to: read the first set of objects from thefirst object store; create a second set of objects to mirror the firstset of objects; and store the second set of objects within the secondobject store, wherein during the operation a checkpoint is generated toindicate a last object of the first set of objects used to create andstore an object to the second object store as part of the second set ofobject.
 2. The method of claim 1, comprising: in response to identify aninterruption during the operation, restarting the operation based uponthe checkpoint.
 3. The method of claim 2, wherein the restartingcomprises: restarting with a next object of the second set of objectsafter the last object, wherein the checkpoint indicates that the nextobject has not been mirrored to the second object store.
 4. The methodof claim 1, wherein the operation is performed as part of a resyncoperation to read the first set of objects from the first object storeto create the second set of objects to store within the second objectstore.
 5. The method of claim 1, wherein the first set of objects arestored within a storage bucket of the first object store.
 6. The methodof claim 5, wherein the operation is performed as part of a migration ofobjects from the first object store to the second object store.
 7. Themethod of claim 6, comprising: in response to the first set of objectsbeing migrated to the second object store as the second set of objects,detaching the storage bucket from the first object store.
 8. The methodof claim 6, comprising: in response to the first set of objects beingmigrated to the second object store as the second set of objects,deleting the storage bucket from the first object store.
 9. The methodof claim 6, comprising: in response to the first set of objects beingmigrated to the second object store as the second set of objects,deleting the first set of objects from the first object store.
 10. Themethod of claim 1, wherein the operation is performed as part of aresync operation, and the method comprising: suspending the resyncoperation based upon a latency associated with client access to objectswithin the first object store, wherein the suspending triggers thecreation of the checkpoint.
 11. The method of claim 10, wherein theclient access to the objects is assigned a higher priority than theresync operation.
 12. A non-transitory machine readable mediumcomprising instructions for performing a method, which when executed bya machine, causes the machine to: read a first set of objects from afirst object store for mirroring to a second object store; create asecond set of objects to mirror the first set of objects; and implementan operation to store the second set of objects within the second objectstore, wherein during the storing a checkpoint is generated to indicatea last object of the first set of objects used to create and store anobject to the second object store as part of the second set of object.13. The non-transitory machine readable medium of claim 12, wherein thefirst set of objects are stored within a storage bucket of the firstobject store.
 14. The non-transitory machine readable medium of claim13, wherein the operation is performed as part of a migration of objectsfrom the first object store to the second object store.
 15. Thenon-transitory machine readable medium of claim 14, wherein theinstructions cause the machine to: in response to the first set ofobjects being migrated to the second object store as the second set ofobjects, detach the storage bucket from the first object store.
 16. Thenon-transitory machine readable medium of claim 14, wherein theinstructions cause the machine to: in response to the first set ofobjects being migrated to the second object store as the second set ofobjects, delete the storage bucket from the first object store.
 17. Thenon-transitory machine readable medium of claim 14, wherein theinstructions cause the machine to: in response to the first set ofobjects being migrated to the second object store as the second set ofobjects, delete the first set of objects from the first object store.18. The non-transitory machine readable medium of claim 12, wherein theoperation is performed as part of a resync operation, and wherein theinstructions cause the machine to: suspend the resync operation basedupon a latency associated with client access to objects within the firstobject store, wherein suspension of the resync operation triggers thecreation of the checkpoint.
 19. The non-transitory machine readablemedium of claim 18, wherein the client access to the objects is assigneda higher priority than the resync operation.
 20. A computing devicecomprising: a memory comprising machine executable code; and a processorcoupled to the memory, the processor configured to execute the machineexecutable code to cause the computing device to: read a first set ofobjects from a first object store for mirroring to a second objectstore, wherein the first set of objects are stored within a storagebucket of the first object store; create a second set of objects tomirror the first set of objects; store the second set of objects withinthe second object store, wherein during the storing a checkpoint isgenerated to indicate a last object of the first set of objects used tocreate and store an object to the second object store as part of thesecond set of object; and in response to the second set of objects beingstored into the second object store, deleting the storage bucket and thefirst set of objects.